Railway-traffic-controlling apparatus



Feb 8, 1927 l F. H. NICHOLSON RAILWAY TRAFFIC CONTROLLING APPARATUS Filed July e,- 1922 s sheets-sheet 1 #-14 ATTORNEY F. H. NICHOLSON RILWAY TRAFFIC CONTROLLING APPARATUS Fel. s, 1927. 1,616541 Filed July 6, 1922 5 Sheets-Sheei'l 2 v INVjENToR:

BY mmm@ ATTQRNEY Feb. 8, 1927.

F, H. NICHOLSON RAILWAY TRAFFIC CQNTROLLI'NG APPARATUS Filed July e, 1922 3 Sheets-Sheet 5 .hl-1 ATTORNEY i The circuits FRANKiH;

'SWITGHLAISD3`^`SIGNTIL|COMPANY, OF' SVSSVALE, PENNSYLVANIA, A CORPORA- TION OF PENNSYLVANIA. 'i i I Y RAILWAY-TnaFnrc-oonrnon Appncationgmed July e,

My. inventionrelates to railway 4trail-ic con# trollingapparatus ofthe ltype lcomprising governing means-on atrain controlled-by energy received on the train from the track- Way.Y v i YI" l L One .feature of. .myinventioniis thepro- ,yision ofapparatuso-Y this' character suitable for use on -a railway thermotive power oiwhich is alternating current.r v Y I Will describeone form of apparatus embodying myinvention,V and Will then point out` the novel@ features thereof in claims. f n-theaccompanying drawings, Fig.' 1 is a vvdiagrammatic--View show-ing Y(one Vform of traingcarried; apparatus embodying remy/in- V.IT-ig, 42.1 is .afdiagrammatioyiewi relation., showing one formof .trackway'iapparatus suitablefor co-operation with the traincarried apparatus shown. in Figli. Figs.V 3 and are vector Y diagrams: showing.y the voltages and currents an d the phase relations thereof in portions oftheapparatus of Flg. l` underi various conditions.y AFig. 5 1s a resonance curve. Y L I f ySimilar reference charactersv lrefer to similar parts `in each of the Views.v

, Referring -iirst to-#Figv the reference characters 2l andzl,V designate the' track rails of a-railway along which tralic normally moves in the directionV indicated by the var,- row. rfhese rails are :divided by insulated joints 3 intoaplurality-off successive track sections, of which only fone-section X`Y is shown inthe drawing- It is understood,

however.,

will` usually, be providedy withA apparatus similar `to that illustrated for section X-y-Y.

Located adjacent the entrance end offse'ction Xf-V'is-,a signal@A Which,-as here;

shown, is of the semaphore-typeadapted-to fcautimWfor y.proceedvl racthe position of -the semaphore @Ording to Jfor thecontrol or this signalare not illustrated in the drawing forfthereason that they 'forni no part ofmy present in# Vvention, and it' is signalY Ais lcontrolled:in accordance-'with present day standard practice through :the Y niedinnl presently-be referred tov4 The-track-section immediately tothe rightaofsectiorrXfY Ais profi-ded With Va similar;,-s-ignal SB. I @a Traci; gse'etion ifi-eff; is j proyided jfith; an;- alternating current traclrcircuit comprising Nrorrorsom'en winKrnsen-ne, 'rnNNsYr-A that in practice each track section` suficient to say' that Vthe fo' the-"track.relays Which-Will 1a22. semaine. 573,100.

a transformer TB thesecondary 4 ofwhich iisfcon'nected across the track rails adjacent the exitend` of the section and a track relay havingfa' Winding connected across the rails ad]acent the entrance end ofthe section.

The primary ot transformer TB is'con' stantly supplied with alternating current -iroma transmission line 7- to 'which such curf rent is furnished. by a--generator 8.?

Y Means are alsofprovided forsupplyin g4 the rai-ls offsection XeY with a second alter-v natin-g current VWhi ch flows in the' same' di y ca l rection in thetWo rails vatany giveninstant, 'Y

andwhich l Willterm the localicurrent. For this 4purpose aresistance 9.ais connected across `vthe* rails adjacent the entrance `end ofthe,

sectiongqa resistance 9b 'is-connectedacross therails at an intermediate point inthe section, and a third resistance -1 9 lis 'connected across'thefrails adjacent the'exit end of" the section.' The local currentis suppliedby a transfer-mer TB, thefprim'ary of which is con-` nected With-A the transmission line 71 through afpole-changerjfdoperated by signal SB..

rlfhe supply of current-'from the secondary 12 of vthis transformer is controlled -by relay C 'RB in thestollowing mannerzf-When relay RB yis* energized, the secondary circutfor transformer TBl' passes through Wire 4,5,

front-point 'of contact/4:4 of relay RB, Wire- `46,resistance 9, track rails 2 and .9A-re'- sistance 9a, andvwire 4Zf-rto the secondary of transi'iormerA Ti. g W'henlftrack relayRBjis de-energized,-tlie secondary circuit for transf" former' A.Tvljpasscsthrough .Wire 45, back j point iet-contact liet, Wire 48,- resistancell trackvrails.Zand-2, resistance .9?, andfwirei a'tol secondary-l2.. It Will befse'en rom the foregoing that. When track lrelay Ris energized, localV current is `supplied throughs ont the lengtlro'tfthe sectionX/-Yyan-dthis' current isof what l will term normalrelm tive,polarity,7 because signal` SB isfthen-in either th'eproceedor the `-camitio'n position, Vfshen track relay RB 1s de-energized, however, vlocal current issnpplied tolth'e rails* currentis of 'what vlWill-lterm freverse relar tive polarity `because signal'lB then' in, ,r-

reversed@ 1,

tivo alternating currents.

crates stopj and so the pole-changer `6 has beenf Y l p heated by frequency but aredisplace'dy vin phase by approximately 900. 'This relay, then, will ybe energized in one direction or the other according as the pole-changer 6 ot `Fig. 1 is in one 'position or theotlier. .Relay controls suitable train governing apparatus which forms no pla-rt ot' my present invention and `which consequently is omitted'iroin theprehzsent disclosure. u AThe lilainents 24: of the amplifiers Kare they are all connected in series. This battery also serves to operate a. motor lil'vvhch in turndrives a! generator Gsupplying die rect current to the plate circuits of the ,sev-

'eral amplifiers as will hereinafter appear.

lt 'will be apparent yat once that. voltages will be induced in the receiving coils ET and FL by the propulsion current'in fthe' tracl; Y rails. .This current has at least two `components, viz, a fundamental kof 25 cyclesand the third harmonic thereof which isofA ?5`cycles,

and voltages due to both componentsvwill be induced in the receivingcoils. vThe propulsion current may also` inc-ludea fslotil'requency which is or a,requencyconsideijably liighertlian the third harmonic. `The 'funda mental or 25 cycle' current is so large compared `with the train controlling currents,

.and the voltages which it induces V.in therew i ceiving coils will beso high, l,that-to avoid overwhelining` or smothermg the iirst stage ampliiiers these voltages `must be suppres'ied ,before .they reach these amplifiers. The third harinoninc or 75 cycle current will ,be

much less in amount than therimdamental or the propulsion current, y but Ait may Jbe much greaterthaiitlie GO cycle train controh ling currents, andwits vieqv-.ency Ais so near Athat oitthc train controlling currents that the presence in the windings otrelay currents duc to this harmonic 1vmust ininiinizcd in order to prevent 'talseoperation Aot the relayl The voltages impressed on grid circuits or the first stage ainplilivers 4by ythe ,75 cycle harmonic" will not be high .enough to smother these ampli'ers, vbut ainpliiication o' the 75 cycle voltageinlthe' lirst stage must beV minimized in order that the second stage amplifiers will not besiiiothered by A'the "l5 cycle output el the i'irst stage ainpliliers.'V lu the vpresent form or my invention, then, I have provided meansk'between the receiving coils F and the k.first stage .amplifiers K, tor suppressing the 25 cycle propulsion current as well as any slot frequency which Jmay exist due to this current, and

Aother means between the first and second stage ampliliers tor suppressing the third harmonic oi' the propulsion current.V ife- -iore explaining these'n'ieans, however,l will state4 what I have assumed thatthefvvoltage and current values ot the'propulsionl energy may be.

' x I have assumed a value of 1000 amperes ot L" y' track coil FT.

a battery 31, andas here shown fby the 75 cycle voltages.

25, cycle )propulsion current asthelmaximum a iount fot 25 cyclelculrrentflowing no 25'cycle voltage' vvillbe'induced inf'tli'e have assumed Jfurther that,lo,n account ottlie autoit'ifansto'ijn'ier efectof the' impedance bonds 20, Vthe normal 'iinbalaiicing ofthe propulsion current'will be very,sliglit,fand that inthe event a' broken rail,"orbond, 4with the attendant large unbalancing of this current, the train controlling circuits `*will be put out of operationyby theblowingofkfuses initraiisformer and track relay leads. Therejoije, it lan excessiveainount of 25 cycle or 7 5 cyclefvoltage ispresentin the track coil FT as well as' .the localvcoilFL, due to abroken rail and fa'neXce'ssive un'balancel of propulsion'curr'ent, the train' control equipment should be' 4stop on 'account' ofthe opening ot 4the traclccircuits, and 'Ano harm"'would ilt even y'it the 'amplifying apparatus'were cycle voltages.' It is essential, however, that underthese conditions there sliayllmbe no false eii'ergila'at'ion" or the train control" relay E y1.5 volts will beind'uced 'lh-e Vsame lcircuits and vprotective means,

paratus,'becau"se tl'ie're must be lno'V phase splitting of the voltages from a'siiigle phase tlie ltwol circuitsmgfrom thereceiving coils to the relay windings. "vTlie amount ol" 75 a 25 lcycle propulsion current is not delinitely known, but l have reason to believe lthat on cycle current present `in open circuit, the third harmoni'cfvoltage in railway generators may be as high as ,3%

of th'e lfundamental voltage. It 'seamsreaf sonable Lto'vsuppose tli'atthe third harmonic curreiitwould be less than 3%, because'the rca-etaiic'eA of the load circuit 4at 'this Ifrequency would be greater `than at25 cycles. There may be other factors', however, such as "the 'magnetization of the transformers,

,etcdlteiiding'tofprolduce a thirdh'ajrmonic A fand l have ytheretore assumed a 109.

one ack," and inducing' a 25 cycle0 voltage in the/local coil 1"* on. the train. So v-long las this currentfdivides equally in tliefti'voi ails, 1'

thered by'itheexcessive 25 cycleandl' however, must be used in'lboth track `and local circuits l of the vreceiving and amplifying ap- 'sourcey ',deliveredf toV the track and 'localrec'e'ivingcoilsl Therefore, there must be no ldiilerences in the electrical characteristics or value of 75 cyclecurrent equal to 3% of the 25l cycle propulsion.current. On' this basis, lf-orulOOO amperes of 25 cycle current, the 5 cycle current will be 30y ainperes. The 75 cyclevoltage delivered tothe gridcircuit of lthe first stage lamplifier ofthe local phase by 30Y amperes of track current is taken as the maximum third harmonic voltage to be hanvdlecl bythe amplifying apparatus. This voltage will be about 8 volts in the local phase, and according to `my earlier assumption, about 1.2 volts in the track phase. Y TheV normal value of 60 cycle train'controlling current is taken as l ampere, and the `60jcycle'voltage delivered to the grid circuit Vof the first stage amplifier as about l volt.

Y Referring new to Figl l, the local receiving coil FL is provided with a circuit which includes, in series, a condenser 35, a reactancecoil Seand a second condenser 33. As

' shown in the drawing, a thirdcondenser 32 is also connected across the terminals'of coil FIV, but' this condenser will be neglected for 'the present. Y The values of the elements constituting circuit a-b-cZ-e are such that the circuit vis resonant at or near thefrequeney of the train controlling currents, whereas Vthe. constantsof the yportion cZ-c are so chosen that this' portion of thecircuit is `Vresonant `at the frequencyiof the fundamenftal of the propulsion current.

The grid circuit of amplifier KL, is connected at points ZV and e in `the receiving circuit, and Asince that part of the Vreceiving circuit which lies betwe'e'npointsv CZ and e is resonant at the fundamental frequency of the propulsion current, fli li'ich I have assumed to be 25 cycles per second, the voltage drop across these point'sdue to currentof propulsion frequen- Vcyinduced in Ythe receiving circuit willv be minimum.; Condenser 35 may be of an im`- pedance having considerable value at 25 cyi cles, sotha't in effect at cycles the complete receiving circuit presents a resistance of rclativelyvsmall 'value1in series with anfiinpedance of relatively large value; and

` lyingbetween points tance and the entire circuitinay be so arsincethe voltage takenV out of this circuit for the'grid of amplifier KL," is obtained from Vacross the resistance (33 and 34), this f voltageis of relatively small value;

At the frequency of the train controlling current, which I have assumed to be 60 cy-l cles,v that portion of the Vreceiving circuit Vrif and c is an inducrai'iged Vthat the value of this inductance at {if} cycles is considerablygreater than* the -pointsjale-e can therefore bev very much value ofthe impedance of this portion' ofV the Acircuitat 25 cycles. Furthermore, since the complete circuit Z-Z-'e' is resonant Vat 60 cycles, a relatively large amount of :GO cyclecurrentwill flow through vthe por- The 60 cycle voltage across greaterthanthe 25 cycle voltage across this branch; in other words, the voltage induced sol that a relatively large proportion of the high frequency voltage induced inthe re-V ceiving coil FL is consumed in overcoming the impedance of this coil. lt follows that the slot frequency voltage. or other high frequency voltage appearing across the points cZ-e is relatively small. Condenser 32 may serve a further purpose in that it can be used lto increase theamplifying ratio of thel complete receiving circuit a-luc-d-e-f.

rEhis result may be accomplished by making he circuit a-b-c-f resonant at or near the frequency of the train controlling current and the branch c--aZ-e resonant at or`v near the saine frequency. Furthermore, by adjusting the circuit a--c-j to resonance at a frequency a few cycles above the tra-in controlling frequency and the branch c-cZ-e toV resonance atA a frequency a fewV cycles below the same frequency, the complete circuit may be made lconsiderably more stable with respect to changes in phase and amplifying ratio when subjected to changes in the frequency of the rent.

lnterposed between Vthe track coil FT and the first stage' amplifier KT, associated ltherewith, is another group` of devices similar Such currents are in a measure short-circuited by the condenser 32 train controlling curto thosejust described and operating Vin the' 'Y same manner toy transmit train controlling frequency to the amplifier and suppress certain frequencies diie to in the track rails. v l i Theapparatus for suppressing the third harmonic of the propulsion current is as fol lows: Considering first the amplifiers fer the 'local phase, it' will be noted that the complete output circuit for amplier KL, includes two branches, the first comprising a condenser 37, a resistance-.413, and a reactor 3S), all Vconnecte-:l in series. The second branch for this ycircuit includes a condenser 3 and a reactor 4() also cpiinected in series. A non-inductive resistance 36 is included in. series with both. branches. The grid circuit for the second stage amplifier' KLZ is conlnected'across reactor O and includes a bloclr-l propulsion current the point GinV reactor .39 for reasons which i will be explained hereinafter.

As hereinbefere stated,l'liave assumed that vthe 75 cycle voltage inputto the firstV stage amplifierinayfreach 'a maximum of l0 Volts. kThe norinal operating input vvoltage'at 60 cycles will *be aboutvone volt. l Con-f sideration of the operating characteristics of:`

the electron tube amplifier Will show that the main problem is to so suppress this 75 cycle Avoltage that the operation of the second stage 'i tube Will not be smothered by the incoming 7 5 cycle voltage. .That is, if any considerable amountof 75 cycle voltage is'allovved to reach .the vsecond stage lanipliier, its cafV pacity vvill be almost entirelyabsorbed by the 7 5 .cycle voltages and the relatively smaller '-60 cycle vvoltage Will not be able to retain Y control ofthe tube and the'train governing relay operated therefrom. An input not to exceed ten volts canbe carried by the first stage tube Without [serious interference With,

the cycle control. Therefore, the 75 cycle voltao'e must be suppressed between the first l D and second stage tubes.;

Referring to the circuit diagram, branch A-B C-D, in the alternating current output circuit of the first stage tube is reso-fl .nant at or near ,75 cycles, and so this branch i may be known as the 7 5 cycle branch. The

parallel branch, A-E-D, is *resonant at a;

lowelj frequency',-preferably lower than-60 cycles,and may be known Vas the 60` cycle"- branch,

Referring nov.T to Fig, 4, which is a v'vector diagram for 60 cycles, the line VA-f-D may represent the 60 cycle voltage across they two parallel branches A-B-eCe-D and AME-D. Since the V,cyclev branch is resonant at or near-,75 cycles, at 60cycles.

the net impedance Will be that of a capacity anda resistance, and the current Will lead the vvoltage .Pr-I). The current through` the 7 5 cycle branch is represented by vector imm. Similarly,- tlie net impedance ofthe (S0. cycle branch ivill be that of an iiiductauce and a resistance, so the current in the (SO cyclebranch will lag behind the voltage vectorA-D, as shown byvector imm. e

The tivo currents, ABD and AED combine to give ii, Which is the current through the,"

resistance 36. The drop` through this lresistance is in phase With currentt and is represented by vector Ar-P. At this point, there l is a third current Z'PMN which 'flows through the cholre coil il and generator 1G to point-D. This currentl represents a Waste Yof energy, and is made as sinall as practica# vvoltage in the tube plate'circuit is ,thegeometric sum of the three voltagesv 'fi-1),

Ar-P, and P-(), Whichy is equal (to the" vector G-ll yThe grid voltage on theriirst stagetubev equal tothe total voltage iii-.thep'late circuit, divided bythe 'amplifying ,ratio cfu' :the tube,- audits phase is. 180 displaced from-that ofthev plate'` circuit voltage. This grid voltage is representedby vectoreg.-

Returning now to vector. A-D, it- Will be' seen that' thefiowfof currentAED through y the circuitAED produces the voltagedrop Y iin-E acrossthe condenser- 38 and the .volt. age drop E-D across the reactortt).` rlhe lattervoitage is'the grid input to the second stage tube.` Likewise,4 the fl'ovv ofcurrent the voltage drop. fir-B across the condenser 37, the; voltage drop l-+B across the resistance 43, andthe voltage drop B+-`C'-D across ,the reactor 39. Y i

It `will befnotecl that a tap has been l Vbranch.` rihe vvalue and ldirection-.of the voltage between this tap and the end of the brought out on the reactor-35H11 the 7 5 cyclel coil is represented byvvv vector'C-l). It .Will p y introduced into lthe gridcircuit of the first lstage tube, so that the voltage across C-D 'voltage @.1

Returning now quired to 'producelthe voltagesrepresented by the vector diagran'i, it Will be iiotedthat is alxvaysa'dded ge'oinetrically tothe input.

be noted; further that the voltage C ,D is

to the grid voltage reif the lvoltage GMI) is in the same general cli- 1 -rection, and isv almost equal to the requiredV grid voltage eg. It is apparent that to ob- :v

tain voltage eg, the voltage e, .ofrproper phaseand amount mustbe'added to voltage C-D. Itis.Lapparentffurther that voltage c kis very much smaller Ythan eg, and that the greaterV share of the input grid Vvoltage is supplied'- by. the' voltagevv Cei-1D, or in other Words by the voltage output of thev tube itself.' The-,circuit is, therefore, regenera- `tive at tSOcycles.4r f

The overall ainplilication V"ofthis circuit up to theiuput of the second stage tube is equal to the ratio of voltagefE-'D to' e,

diagram, the ainpliiicationisequal to 58.1

and inthe case illustrated by this vector i Referring noni to Fig. 3, Whichvis the vec-17v tor diagram sho'vving'th'e voltages-,and currents at 75 cycles, and starting With approximately Athe same value for the voltage A-D, f

it Will be seen that both currents inthe'par# allel branches ofthe load circuit no'iv` lag behind the voltage A-D. Th-e current through the 75 cycle branch is considerably i'ncreas'ed'over that atV (SO cycles because cir- Acuit ABe-C-D is near resonance at 75 cycles;`r

resistance 36 and the tubeis given by vectors The .total .current t', is .likewise con-( vsiderably increased.` The drop through the j 4i-P and P-f), respectively, and the total i Y voltage in the-plate circuitis given'asbefore by vector O-D. 'The grid voltage eg is ob-Q-l`v tained as before by dividing the total alter- Aiao les *j .Y Y j Considering the vector diagramv at 60 Y cycles,it will be noted that at frequenciesY n-atingcurrentplate volts `byfthe amplify-,VV

ing 'ratiov of the tube. Y Y

- Itrwillfbe noted thatthe increased current .through the 7 5l cycle"branoh, A,produces an increased 'voltage across C-D ofthereactor,

and furthermore, the phase .of this `voltage khas shifted` about 90O ina clockwise direction; i Y

Proceeding asrwith thee() cycle diagram, andsubtracting vectorC-.D from vector eg,

"it will be seenthat the former no longer-as-v if s ists the vector eV in supplying the necessary gridvoltage eg. It will be seen that at 75 i' H jcycles, the output ofpthefainplifier is used to is x oppose the input, andthe circuit is there Y foredegenerative 'at this frequency; 4,

Theovera-ll amplification of the circuitvat gzcycles'V is equal vto the ratioof E-V-D toa;- andisvery much smaller than at 60 cycles.

Using tlieval-ues given on this diagram, theVV n amplification is equa-l to 3.29.

Q The selectivity ofy this circuit lbetween GO cycles and 75 cycles is Vequal tothe ratio of thefftwo amplification ratios, Vor using thee valuesnoted onthe diagram, y.is equal to 58+3.29=17.6. i 1 ".Consideringinow'some of the functions of the detail-parts of this circuit, it willbe apthe selectivity parentthat resistance 43 may be usedto determine the amount ;of current iiowingfin the 75 cycle'branch. They amount ofcurrent of regeneration orv degeneration.

flowing in the 75 cycle branch determines the Vvoltage acrossiCj-Dnvhich is the regenerative 'or degenerative voltage. a Therefore, this resistance can be used to adjust the amount Resistance 36V has `two functions. One

function'isto minimize changes-in thefvolt age` and vector relations in thescircuit due to change of tubes. The internal impedance of thefelectron tubeyaries in different, tubes vloadcircuit-,f which includes resistance 36is .f

of thesame type. If the Vresistance Lof, the

large comparedwith the internal impedance Y of tlie tube, tlienlvariations in the'impedance -of tlie tube will not have much effect upon Ythe `voltage or veetorrelaticns existing inthe complete circuit. 'Y

. TThe second functio'nof resistance 36 is to 50V V'Iication ratio of the'complete circuit is. a

'determine the frequency at which the amplis "maximum,VV In otherwords, this resistance can be, used to determinerwithin limits the frequency at which the circuit appears to be resonant;

highertha-n 60 cycles, vector C-D will rotategin a clockwise direct-ion andincrease in length. At frequencies lowerrthan 60 cycles vector. C-D will rotate inra counter-clock-V wise direction and willdecrease in length.

It is apparent that for frequencies a fewk Y cycles. less than 60 cycles vector C-D is movlinginto a` positionl in which a vector of Therefore, V62 cyclesandif there `is not too great a ycycles, 'In a similar way, vector be made so shortan'd the angle between 36 should be increased in value.

given length is most effective as a regeneraytiv-er voltage because it is moving into a position ofexaet phase'v agreement;witheg.V ut

opposing tliis''effectis thefshrinkingf inY length of C-iD, as itinovcs into-phase agree# stands a little above vectore'g, or aboutai-n the position shown .by diagram.- Non/Y, if at 60 cycles th-e values of the presente() Cycjf' `7c Y mentfwith eg, and a consideration of-all'quan-f Y I tities involved willl showithat vfora givenv I output, 'c is theshortest when lvector C-DH resi'stance rfeactance, capacity, etc., aresucn".y

that vectorCD-coincides in phase with@g at some'frequ'ency higher rthan* 60 cycles vectoi` C-Df would voccupy Y the Y position` position of maximum' regeneration.v Theref fore, the vpeak of the apparent resonant l'curve wouldoccur at a frequency higher than 6() cycles".` 1 t i f They frequency at lwhich vector C-DisV shown by thepresent diagram, which Yis Vthe most effective asa regenerative voltage-de pends-largely upon the geometry of the triangle inadeY up of voltages (lj-D,A eg, and. e; i Moreparticularly-it depends upon the angle between vectors CV-D and yeg. Thisangle l between C D andjfeg `can be determined Within certa-in limits'by the length Aof vectors AP-and P-O, andthislength can Vbe dei termined orV adjusted by adjusting *resiste ance 36. Therefore, the frequency, near (SOl cycles,at whichmaximum regeneration, and? g therefore maximum amplification, will occur,'can be'determined by the'resistanee 36'.

As an illustration of the second functionV f of resistance 36, suppose for the 60 cycle diagram vector AP were increased in length until vector. O-l) were parallel to vectorA` C-D.V Thenivectors eg and C-D wouldcof incide in phase,fand vector e would be thel arithmetical difference between these two vectors'. Now at '62 cycles vector C-D has increased in length, 'and Voccupies the positestV and'calculati'ons showthat for this position and length of vec-torC-*D the length of vector e is aininimum fora given output. the regeneration is a maximum at vchange. in the other parts ofthe circuit, the circuitfamplification will be greatest at 62 A-P may resonance curve illustrating the values just referred to, and from whichit willbe seen that the resonance peak occurs at 59 cycles. In any circuit used for signaling or train 'maximum amplification tionshown by the present diagram But Y Fig. 5 is a Y circuit. shown.

fl t),

reien controlling purposes, in which there is an element used toV protect against energizationY from a foreign source, itis essential that the This requirement is niet i-n'the It will be vnoted thatV at 60 cycles the greater share of the required grid voltage eg is supplied fromthe output of the first stage tube, by the voltage C-D If the operative.

`protect-ive circuit A-B-C-D v0peiis,.theV

voltage C-D becomes' Zero,xand the required input voltage ,e must then equal Vthe grid,

voltage cg if theoutput is toremain constant. If voltage e is limited, as it will be in the caseof Vthe train control circuit, not enough voltage will be. applied to the gridof the first-,stage tube to keep the `train control relay energizedV through the'amplifying cir- ,1 cuit. A stop signal-will result.

If, under the conditions cited above, a large 75 cycle voltage is applied'fto the first stage tube,'tlie operation of the second stage tube will-be smothered by the 75k cycle ,output of l'the first stage tube.- Therelay thereforewiil notpick-up on anexcessive amount offcycle voltage. l

If a small amount of 75 cycle voltage is applied to the-first sta gc tube ofA one phase and the protective'cirouit of this phase only is open, there will' be somer phase splitting of the input voltagesl-J' the track and local phases, andthe relay may be provided with twocurrents separated'in phase by vapproximately 500. The protective circuit of one phase beinglintact, however, not enough 75 cycle energy will be deliveredto the respective winding of the relay to cause it to pick w comprisingmeans forsupplyingthetrackway withA alternating propulsion current and 1f both protective circuits areopen, there will be no phase splittingof-tlie75 cycle iii- Y put voltages, whichy arefrom a single phase ,source and the relay will not be energized because the 75' cycle currents through its windings are of the saine phase. i

VAlthough Y I have herein shown land described only one form of apparatus embodying my invention, it isunderst'ood thatvarious changes and modifications may be'inadetherein within the scope of the appendedy claims without departing from the spiritand scope of'my invention. 1 p Y Having thus described my invention, what I claim ist' 4 .Y i

l. Railway Vtraffic controlling apparatus comprising means for supplying the trackp way with alternating propulsion current and alternating train controlling current differingin frequency', traffic governingvmeans on a train, and apparatus on said train for supplying saidztraiiic governing means 'witha resonant rise of voltage at the train controlling frequency` and witha resonant decrease of volta-ge at the propulsion current fre- `ing .in frequency, a coil Ajon a train receiving vvoltages due tosaidtracliway currents, traffic y governing apparatus on the train' suppliedv plied (with voltagerbyl said receiving coil.,`

lacrosssaid'freceiving coil for shunting fre'- p' 2. Railway tiaflic controllingapparatus comprising in'eans forV supplyingthe trackwayiwitl'i alternating propulsion current and alternating train controlling current "differ-- with 'voltage bysaid receiving coil, and a bypass across said receivingcoil'resonant at the v propulsion current frequency.v i f Railway t ailic controllingv apparatus" .comprising means, for supplyingtlie track'- way with alternating propulsion.currentand'.f

alternating rtrain controlling ,current-differing infrequency,=a coil on aftrain' receiving if voltages due to saidtraclwaycurrents-traffic" governing apparatus on the :train supplied g with voltage by said receiving coil,ua"by-pass across said receiving coil resonant. at'the pro--. pulsion` current frequency, and a condenser vfor timing' saidiby-pass and said-receiving coil topara'llelresonance 'at thetrain coii-` trollingcuifrentfrequencyA 4l'. Railway tra-flic. controlling apparatus comprising means forzsupplying'the trackifway with alternating propulsion current and I alternating` train controlling current differing in frequency, a coil on train-receiving voltages due .to'saidtrackway currents, 'traffic vgoverning apparatusgonthe train sup-V plied with voltage :by said receiving coil, an 1 element linterposed between 'said receiving? coil and-said governing'apparatus` and tuned 4to series resonance at the propulsigri current frequency, l:and means for ltuning. saidi element'and said coil to parallelA resonance at Y thek train controlling current frequency. `Ar

5. Railway` trallic,A controlling apparatus a Aley-pass across said 'receiving coil resonantI at .the vpropulsion current frequency, and a secondi by-pajss across said receivingv'coil forshunting frequencies higher than either th-efpropulsion'or train lcontrolling current Y frequencies l 'f y y 6. Railway traffic controlling" apparatus' comprising meansfor `supplying the track .way with alternating propulsioncurrent and alternating. train'` controlling' current differing in frequency, a coil on a train receiving:V

voltages dueto said trackwaycurrents, traffic governing apparatus lonthe train supplied'with volt-age byrsaidfieceiving coil, a by-passacross said receiving'coil resonant at the proplusion current frequency," a condenser for tuning sa'id-by-passand said-coil to parallelfresonance at 'the' trainl controlling current "frequency, and a second by-pass connectedin seriesacrosssaid input circuit, f

a second vcondenser interposed insaid circuit A- between said .coil and the point atWhich Y said reactor isjconnected with the circuit, a third condenser connected across the termi- 7onalsof. said coil., and. train ygoverningmeans controlledby tlieoutput circuit of saidlam- I Y. que-ncies higher than either thepropulsion or o V- :fthe train controlling currentfrequencies.

f-. l7. Railway tra'flicY controlling apparatus comprising means for supplying,tlie"track 5 way-with alternating propulsion current and alternating train controlling current differing in frequency, av coil on a Atrain receiving voltages due to said trackway currents, traff fic',V governingapparatus on the train sup- Jlj-'l plied with 4voltage said receiving. coi-l,

pliiier.. y' 1. y e l2. Railway. traffic .controllingapparatus comprising a trackway,meansefoiz iSupply-I andineans interposed betweensaid coil and Y saidrapparatus forshunting from said app paratu'sfvoltage created i 'saidl propulsion current..4

ingl thereto alternating propulsion current fand v-alternatingr, train controllingl .current diiferingin frequency, a train provided With means for receiving .voltages due to said e tiackway c currents, .traffic governing lmechai Vn'ism on saidl train,l a v-irst stage amplifier and af secondstage amplifier interposed between said receiving .means and said .governil ing.,mechanism, apparatus located `between saidfvreceivingmeansand Vsaid-:firststage.

amplifier forsuppressing. voltage due -to the fundamental of said propulsion current, and.7

` other -apparatus locatedjbetween Ysaid first voltage due trackway, governing apparatus. on the train v'supplied with voltage by saidfcoil, and .a

v `by-pass-acrossfsaid coil resonantfa't, the. fre-,v Y. f .ce ,queney ofionerof saidtrackway currents..

` jlO, Railway: traffic .controlling apparatus.' acoinprisinga 'trackway, means for supplyingfthereto alternating -propulsionmcurrent5- 'plii'ier voltages due tofsaid train ycontrolling current and the third.harmonic-of said vpro- 'and'..alternating train controlling current l" fd'iiferingin frequency, atrain provided-withv @a coil receiving voltages inductively from said trackwaycurrents, an`ainplifier on said f Y train having lanjinput circuits'uppliedwith voltageby. saidcoil, a condenser y and a. re-

50 actor connected inseries across. saidrinput circuit, a second condenser interposed', in said circuit-between, said coil and `the point at which `said-reactor is-,connected with. the

. "f'f'circuit, fand train governing, meansy 'con- `5177',trolledQby the output.circuit'o'fzsaidxam-V llQR-ailway traffic controlling; apparatus' comprising a trackway, meansfor supplying thereto,alternating propulsion; current ,and 'W' alternating train controlling cur-rent differing-in frequency, a traiiiprovided with a c'oilfreceiving voltages inductively from said tracjkway currents, van amplilieron Vsaid train 1Q' n havinganinput,circuit supplied With'volt-V. 1 fr id `coi l,fa.condenser and a reactor n said coil dueto V8.5 Railway .trafic controlling apparatus. Y 'comprising ga trackway,pmeans vfoifasupplying thereto alternating propulsioncurrent and y alternating Atrain controlling currentdiffering` in frequency, a trainprovided with an amplifier, .a plate circuit .for :said amplifier having two branches eachiincluding al YseY i condenser and a reactor, theifirst branch being resonantpat approximately. the frequency of the .thirdfliarinonic-ofrsaid propulsion cur-- rent and the second branch. being resonant al' approxiii'iately thefrequency offsaid train' controlling current, meansjon said train for impressing across a point in the reactor of saidiiretbranch and the grid of said amplifier Vvoltages ydue vto saidetra'incontrolling- Y current' and the third harmonicl 'off said Ypropulsion current,and .train governing means controlledby the voltage" across the reactor in the secondof said plate circuit branches.` 13. Railway p 'traffic 'Y controlling apparatus` comprising a traclway,lmeaii s for supplying thereto alternating.. propulsion currentv and alternating train controllingy current differing in frequency, a train --providedwith an amplifier, a plate circuit for sai'damplifier having two branches eachincluding a con-y lll() e' `denser and a reactor,.the first branch beingH resonant at approximately the frequency vof the third harmonic of saidfpropulsion current and tliesecond branch being resonant f at approximatelyihe frequency of said .train controlling current, means onsaid trainl for impressing acrossja point in the reactorof said first branch and the grid of said am-` i' pulsioncurrent, a' second. amplifier having a the-,reactor in vthe second of said branches, and train governing means controlled by the plate circuit of said secondV amplifier.

HuNV

.grid circuit-supplied bythe vol-tage acrossY Y .Y 'lll-Railway traffic controlling apparatus comprising a trackway, means .for supplyf ving thereto alternating. propulsionV v current yand alternating train controlling. current difi with.V voltages due to said train controlling current and the thi'rdharinonic of said propulsion current, means associated with said ampliiier for regeneratively feed-ing. back into said input circuit currentof train controlling frequency and for degenfrativel'yfeeding back into said input circuit currentV ofthe frequency of the third liarinoiiiejof'ld'JrV ing means controlled by the output circuit of said:Y amplifier.

15.` Railway traffic controllingL apparatus comprising a trackway meansi for supplying thereto alternatingy propulsion current and alternating train controlling current differingin frequency, a train provided` with. an amplifier, means on said train' for supplying the input circuit of said amplifier with` voltages due to said train controlling curient andthe third harmonic of said propul- Asion current, means associated vwith said amplifier for degeneratively feeding back into said: input circuit current of the frequency of the third harmonic of said propulsion current, and train governing means conirolled` by the output circuit of said amplier.' f V 16. Railway tra-flic controlling apparatus comprising a traclrway, means for supplying thereto two alternating train controlling. currents ofthe saine frequency but differing inv phase as Ewell as alternating propulsion Vcurrent differing in frequency from the train controlling currents, ygoverning means on a train includingv an induction motor relay having two stator windings,and apparatus on said ltrain controlledbyl said. traclrway currents for supplying saidA windings witii currents of the same. frequency and phase relation as said train controlling currents andl for preventing the supply to said windingsV of currents due to said propulsion current.

17. Railway traffic controlling apparatus comprising a trackway, means for supplying thereto two alternating train controlling currents of the same frequency buty differing in phase as well as alternating propulsion current differing yin frequency from the train controlli-ng currents, a trainprovided'with rtwo coils'receiving voltages due to said two'- ti'ain controlling currents respectively and also voltages diie to said propulsioncurrent, two firststage amplifiers on said train one for each coil, means interposed between each coil and the associated first stage amplifier for supplying Vto the amplifier voltage due to tlie-v train controlling voltage receiving such coil ,and suppressing the voltage received by the coil due to the fundamentalof said propulsion current, two

stage amplifier, means interposed between each first stage amplifier and the associated second lstage amplifier for supplying the second stage amplifier with voltage due t0 the train controlling current delivered by the first stage amplifier and suppressingthe voltage delivered by the first stage amplifier due to the third harmonic of said propulsion current, and governing means on said train including an induction motor relayliaving two windings `supplied respecotlier frequency inthe trackway..v

second stagey amplifiers on said train one for each firstv tively with currents by the output circuits ofpsaid secon-d istage amplifiers.v

1:8., 'Razilwaytraffic controlling appar comprisinga. trackway carrying currentsdiffering: in frequency-,a train carriedcoil receiving voltages due to currents` in' the atus: Y

trackway governing apparatus on the train supplied with voltagevby said coil,` a4 bypass across said: coil resonant at fthe freq'iiencyy of oneofsaid trackway currents, and

means for tuning sai-dfby-pass a-nd` said coil to resonancel at the frequency of another of said tiiaoltway currents.A 'I

19.5.Railway traiiic controlling apparatus comprising a. tracltwaycarrying currents differingin frequency, train carried governingapparatus, and means on; the ytrain for crease of voltagedue tocuirent of one frequencyl the tiaclrwayY and with a resonant decrease of voltage `due to current of an- 20.. Railway traffic controlling apparatus comprising a traclway carrying currents dfferingin frequency,train carriedv governing apparatus, amplifying means on thel lsupplying said apparatus with a resonantin--- train for supplying energy to said governing apparatus, and means onthe train for supplying-said amplifying means with Val resonant increase of -voltage due tof current of one frequency in theitrackwayaiid with a resonant decrease of voltage due totheV current of another frequency inthe trackway. n

2l. Railway traffic controlling apparatus comprising means for supplying the trackway with alternating propulsion current andalternating train controlling current differ-f ing in frequency, traincarried governing apparatus, amplifying means on the train for supplying energy tol saidgoverning apparatus, andy means ,on the train for supplying saidf amplifying means with a resonant rise of voltage-at the frequency. of the tra-in controlling current. and witht a resonant decrease of voltage at the frequency of the propulsion current.v l i 22. Railway comprising means for supplying the trackway witli alternating piopulsion current and alternating train controlling current differing. in frequency, traiiic governing appaiatus on the train, a coil on tlie train receiving voltages due to said trackway currents, amplifying'ineans interposed between such coil and said governing apparatus, and a by-pass across said receiving coil tuned to resonance at the frequency ofthe propulv sion current.

23. Railway traffic controlling apparatus comprising meansk for supplying the trackway vwith alternating propulsion current and alternating train lcontrolling current dieringin frequency, traiic governing ap-` los l iio traffic controlling apparatus.

A'fparatus on the train, a coil ontliel trainfreresonance at'tlie frequency ot' tlie propulsion current, and means for tuning. said ley-pass and` sa-idlcoil to resonance at the frequencyv fof the train con-trolling current.V

Y wr,

comprising a tacliwayl carrying currents lceiving voltages dueto said trackway cur rents, amplifying means interposed, between -such coil/and said governing apparatus, .a

by-pass across i said .receiving 'coil `tuned to 24. Railway tiali-c controlling apparatus differing in frequency, a train'carried coil receiving voltages due to `currents in the trackway, governing apparatus on tlie train,

,amplifying means interposed between saidl ycoiljandrsaid governing apparatus, anda *by-pass acrosssaid coil resonant at the tre- Q-quencyV of one of said'traclrway currents.

Railway trafiic'controllingV apparatus Vcomprising a" traclway carrying currents V(littering inV frequency, a train carried coilv receiving voltages' due :to vv currents in tlie vtraclmiay," governing apparatus on the train,

amplifying means. inteiposed between said coil and said `governingapparatus, a lay-pass f across said coil resonant at tliefrequency Vfof fone of said trackway currents, and meansfoi-'tuning saidcby-pass and said coil to resonance at tlie frequencyiof another of said trackfway currents v Y 26.. Railway traffic 1 controlling apparatus comprising a trackway, ineans for supplying Vtlieret'o'two yalternatingtrain controlling currents offth'e saine frequency but differing Yin :phase:Y as well as alternating propulsion current differing in frequency from tlietrain controlling currents, governing nie-ans on vthe l.train including anl induction motor relay Y l fliavin'g two stator windings, apparatus on y '40' n supplying said stator windings with currents the train including two receiving coils :tor

olf'thefs'a'me frequency and pliase'relation as saidtraiii controllii'ig currents, and a vlay-pass VVVacross'eacli receiving coil tuned to resonance at tlierfrfrequcncy Vof said'pi'opulsioii curfrent. Y

i 27. Railway traiiic controlling apparatus coin risinv atrackwaV means. for su 3l in" v controlling' currents.

tliereto two, alternating train controllingV currents or tlie same frequency but differing in pliase as well as alternatingV propulsion current differing iii fi'eqiieiicy-from tlie train 'controlling currents, governingV means on tlieztrain -includingan induction motor re-i; layliaving two vstator* windings, apparatus on tlie train including two receiving coils tor supplying, said stator windings'pwitli currents of tlie sameA frequency and phase relation yas said train controlling cur*v rents, a ley-pass across each 'receiving coil tuned to resonance at tlie frequency of' the g propulsion current, and means lorA timing eacli bypass-and tlie associated receiving coil to resonance at .tliefirequency of saidxtrain 28. Railway traiiic controlling` apparatus comprising a traclway, means for'supplying -thereto alternatingpropulsion current and alternating trainrcontrolling current diiiering in frequency, a'train carried 'receiving'A coil, a train carried amplifier having an input circuit connected with said receivingV coil, trailic governing means onftliertrai'n controlled by the output circuit of said aniplitier, andv a by-pass across said receiving' Yao 'i coil tunedy to resonance at tlie frequency oi tlie propulsion current.

29./Railway traffic controlling apparatus comprising a trackway, means for supplying tliereto alternatingpropulsion current and propulsion current, andl means for tuning said byfpass andsaid receiving coil to reso so l tuned to resonance attlie frequency of the l nance -at tlie vfrequency of tlie trainV con,u

trolling current. Y in testimony` wliereofl aliix niy signature. c

riniui; ii. VNici-ieinen 

